I have chronic, for many years intractable self doubt and a hesitation of having a self - I wonder if that imposter syndrome comes from this space - but it is more than that, by a long shot really, but I don't have the words to explain. I was stuck spinning my wheels for a long time. The abuse as a child meant I didn't get to develop a self - it started really young - but then the little bits of self that I had got buried deep in order to survive and rarely surfaced, and were fleeting when they did. I doubted myself so much I felt/feel that my breathing was all wrong. I doubted myself so much that I said nothing - just repeated things I had heard and read from other places. I doubted myself and my feelings so much I ate and was in a food coma so much of the time so I didn't have to feel how bad I am/was. I was terrified to make any decisions. The self doubt is still crippling at times but it doesn't keep me frozen as much anymore. I still do the fawning things at time and it will take awhile to step out of that.
That Annihilation thing - I so get that on a deep visceral almost cellular level.
I have had to grow different parts of the brain and create a different physicality to actually be here.
You could never have a thought, or a feeling or an opinion until you knew it would be accepted - and if not it was swallowed down.